With 60 miles of trails and nearly 6,800 acres of both natural and developed park area, the Mission Trails Regional Park has something for everyone. Some trails in the park are used for horseback riding, so it's recommend to stick to those marked only for running, hiking and biking. One such option is the San Diego River Crossing Trail, a moderately challenging 2.6-mile one-way route that, as the name suggests, crosses the San Diego River. High water levels in winter and spring may cause the crossing to become impassable, though, so plan accordingly. Photo credit: David Cooksy